As the detection sensor mounted on the vehicle door, a technology described in JP 2010-236329A (Reference 1), is known.
The detection sensor described in Reference 1 detects an obstacle and avoids contact between the vehicle door and a person or another vehicle.
However, the usage of a detection sensor in the related art is limited. Therefore, it is necessary to provide. Therefore, it is necessary to provide a plurality of detection sensors according to the respective uses on the vehicle. For example, for the purpose of avoiding contact with an obstacle, a detection sensor for detecting the obstacle is attached to a vehicle door. The detection sensor for detecting a hand is attached to the vehicle door for the purpose of enabling an operation of the vehicle door by detection of the hand. However, when the vehicle door becomes multi-functional, the number of detection sensors increases accordingly, which may be lacking in the space to install the detection sensors. Thus, a need exists for a detection sensor which is not susceptible to the drawback mentioned above.